Interference mitigation

Abstract

A PLC modem (131-133) is prompted to increase, starting from a predetermined minimum transmit power, a transmit power of data transmission on a PLC channel (112) at a given time or time period defined with respect to a mutual time reference of a DSL channel (111) and the PLC channel (112). A DSL modem (121) is prompted to measure a signal-to-noise value at the given time or time period defined with respect to the mutual time reference. Mitigation of interference 190 between the PLC channel (112) and the DSL channel (111) becomes possible.

The invention claimed is: 
     
       1. An apparatus to mitigate interference between a Digital Subscriber Line, DSL, device and a Power Line Communication, PLC, device, said apparatus configured to:
 provide, to the PLC device, a first instruction to increase a transmit power of data transmission of the PLC device during a measurement period, 
 provide, to the DSL device, a second instruction to measure a signal-to-noise value during the measurement period, and 
 provide, to the PLC device and to the DSL device, a mutual time reference in which the measurement period is defined. 
 
     
     
       2. The apparatus of  claim 1 , wherein the apparatus is further configured to:
 receive, from the PLC device, an indication of the measurement period and the transmit power. 
 
     
     
       3. The apparatus of  claim 1 ,
 wherein the apparatus is part of a network management system, or 
 wherein the apparatus is co-located with either the DSL device or the PLC device. 
 
     
     
       4. The apparatus of  claim 1 ,
 wherein the apparatus is configured to provide the first instruction as part of a sensitivity test. 
 
     
     
       5. The apparatus of  claim 1 , wherein the apparatus is further configured to:
 obtain a control message indicating that the DSL device is transitioned from Initialization to Showtime, and 
 provide the first instruction while the DSL device is operating in Showtime. 
 
     
     
       6. The apparatus of  claim 1 , wherein the first instruction is to increase the transmit power of the data transmission of the PLC device from a predetermined minimum transmit power. 
     
     
       7. The apparatus of  claim 1 , wherein the apparatus is further configured to provide, to the DSL device, a third instruction to initiate a crosstalk estimation. 
     
     
       8. The apparatus of  claim 1 , wherein the apparatus is further configured to provide, to another PLC device, a fourth instruction to reduce a transmit power of data transmission of the another PLC device during the measurement period. 
     
     
       9. The apparatus of  claim 1 , wherein the apparatus is further configured to provide the first instruction to a plurality of PLC devices depending on an expected interference from the PLC devices. 
     
     
       10. The apparatus of  claim 1 ,
 wherein the apparatus is further configured to obtain, from the DSL device, an indication of the signal-to-noise value measured during the measurement period, and 
 wherein the apparatus is optionally configured to compute a value of a set transmit power for use by the PLC device in consideration of the measured signal-to-noise value. 
 
     
     
       11. The apparatus of  claim 1 , wherein the apparatus is further configured to provide, to the PLC device, a fifth instruction to reduce the transmit power of the data transmission to a set transmit power, at least for frequency bands used by the DSL device. 
     
     
       12. The apparatus of  claim 1 , wherein the first instruction to increase a transmit power comprises an instruction to increase the transmit power gradually, thereby establishing a plurality of different transmit power values during the measurement period. 
     
     
       13. The apparatus of  claim 12 , wherein the second instruction to measure a signal-to-noise value comprises an instruction to measure the signal-to-noise value for each of the plurality of different transmit power values during the measurement period. 
     
     
       14. The apparatus of  claim 13 , wherein the signal-to-noise values associated with different transmit power values collectively comprise a sensitivity of the DSL to crosstalk. 
     
     
       15. The apparatus of  claim 14 , the apparatus further configured to provide, to the PLC device, a maximum permitted transmit power based on the sensitivity. 
     
     
       16. A method of mitigating interference between Digital Subscriber Line, DSL, device and a Power Line Communication, PLC, device, said method comprising:
 providing, to the PLC device, a first instruction to increase a transmit power of data transmission of the PLC device during a measurement period, 
 providing, to the DSL device, a second instruction to measure a signal-to-noise value during the measurement period, and 
 providing, to the PLC device and to the DSL device, a mutual time reference in which the measurement period is defined. 
 
     
     
       17. The method of  claim 16 , further comprising:
 receiving, from the PLC device, an indication of the measurement period and the transmit power. 
 
     
     
       18. The method of  claim 16 , further comprising:
 obtaining a control message indicating that the DSL device is transitioned from Initialization to Showtime, and 
 providing the first instruction while the DSL device is operating in Showtime.